Mechanical rabble device



L. B. SKINNER. MECHANICAL RABBLE DEWCE.

IIN.

Patented J'llll 20, 1922.

2 sHEET*sHEET 1 Lew/s B. Skinner.

L. B. SKINNER. MECHANICAL RABBLE DEVICE. APPLICATION FILED sEPT.27, 1920.

Patented June 20, 1922.

2 SHEETS-SHEET 2.

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LEWIS BAILEY sKrNNER, or DENVER, coLonADo.

MECHANICAL RABBLE DEVICE.

Specification of Letters Patent. Patented June 20, 1922 Continuation of application Serial No. 407,702, filed September 2, 192e. This applimtionl filed Septembe 27, 1920. Serial No. 412,993. K

To all w71 om t may concern:

Be it known that I, LEWIS B. SKINNER, a citizen of the United States, residing at Denver', in the county of Denver and State of Colorado, have invented certain neW and useful improvements in Mechanical Babble Devices; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as Will enable others skilled in the art to Which it appertains to make and use the same.

This invention relates to mechanical rabble devices for use in roasting and calcining furnaces generally `wherein heated material is stirred and advanced along a hearth. y

The invention has to do especially with rabble mechanism wherein a revoluble upright shaft carries one or more transverse arms mounted at right angles to the shaft and adapted to support a plurality of rabble teeth (also termed rakes, shoes, or plows), each arm comprising portions eX- tending in diametrically opposite directions from said shaft, and both these oppositely extending portions being adapted and arranged to support. the rabble teeth above referred to. Babble mechanism of this design has certain practical advanta es, among which may be mentioned the "act that, where the rabbling of viscous or sticky material is involved, the rabble teeth may be spaced apart' along the supporting double arm sufficiently to largely prevent the viscous material from bridging across, Without lessening the effectiveness of the rabbling performed or reducing the hearth area swept by a single rabble arm carrying the same number of teeth close together.

rhe present improvements relate to a double arm rabble structure of the general character described in Which-*said oppositely extending arm portions are coinbined construction of particularly advantageous design, which can be assembled With the upright supporting` shaft, or removed therefrom, easily, expeditiously, and with a minimum interruption to normal furnace operation.

Notivithstanding What has been accomplished in the Way of providing rabble apparatus that Will stand up under the severe conditions of heat and corrosion to which such apparatus is subjected in service, more in an integral unit of sturdy, rugged or less *rapid deterioration of the rabble parts eirposed tol mechanical Wear and corrosive influences in the furnace is inevitable; so that fairly frequent repair and replacement must be iexpected and provided for in actual practice. This is particularly true of the rabble teeth themselves, since the conditions of service to which they are subjected are especially severe and cause relatively rapid destruction of the metal castings commonly employed for these members. Removal and replacement of the rabble teeth and arms necessitates stopping or checking furnace operation for a period of time Whose length depends upon the facility and expedition With which the required changes can bemade. While the vchanges are being made, the furnace doors have to be open to afford access to the rabbles. This subjects the Workmen to heat and obnoxious gases; and it also dilutes and thus lovvers the value of the furnace gases by admitting false air into the furnace. lt is important,

therefore, to reduce to a minimum the time required to remove and replace defective rabble parts. f f

Not only is it important that the various parts of the rabble apparatus be capable of being assembled and disassembled quickly but it is also exceedingly important that after the various parts are assembled they may be quickly and positively locked together in such a Way that they vvill not accidentally become loosened. Y

Accordingly it is a general object of this invention to provide improved double arm rabble apparatus characterized by features of construction enabling the double arm as a unit to ybe assembled with or removed from its upright actuating shaft easily and expeditiously, the arrangement being such that, in assembling the parts, the arm is practically self-positioning on the shaft by a simple thrust movement and is quickly and positively locked against movement either longitudinally or about its ovvn axis by simple locking means not dependent uponV parts which through Wear or accidental breakage will permit the locking means to become loosened and the assembled parts of the apparatus thereby to come apart.

Another object is to embody the foregoing and other desirable characteristics in a rabble mechanism having provision for internal cooling, while at the same time attaining simplicity Y and' ruggedness in a construction relatively'free from liability t0.

get out of order.

With the foregoing objects in view, as

well as others which will'become apparent scribed in connection with a typical practical embodiment illustrated inthe accompanying drawings and will then bey more particularly pointed out. Y

Generally described, apparatus constructed in accordance with the principles of the invention comprises an upright revoluble shaft Vtransversely,apertured to receive a rabble arm which can be thrust longitudinally through the transverse aperture of the Vshaft until abutment means carried by said rabble arm intermediate its ends, specifically an approximately central enlargement, most desirably of circular cross-section and having a tapered bearing'surface, engages a coactingsurface in the apertured portions of said shaft. Operative engagement of these surfaces denotes proper relative positioning of the parts, which may be locked in position in any suitable manner, but most desirably by means directly engaging the rabble arm and shaft and acting to draw -the arm and shaft abutment surfaces firmly and positively together, such locking means, in its best embodiment, being structurally separate kfrom the other parts of the apparatus.

In the accompanying drawings, Fig. 1 is a side elevation and Fig. 2 is an 'enlarged end view (looking from the left in Fig. 1), vof rabble apparatus embodying the invention;

F ig. 3 is an enlarged sectional view on line 3 3 of Fig. 1;

Fig. 4 is a fragmentary enlarged sectional view on line 4-4 of Fig. 2;

Fig. 5 is a fragmentary enlarged sectional view on line 5 -5 of Fig. 1; Y

Fig. 6 is an enlarged sectional view on line 6 6 of Fig. 1; and

Fig. 7 is a fragmentary enlarged sectional view on line 7-7 of Fig. 3.

The 'specific embodiment of the invention illustrated in the drawings is what may be termed a T rabble arm, which I have found to offer important practical advantages when used in mechanical furnaces for making muriatic acid and salt cake, such for example as those illustrated in my prior copending applications Serial N o. 359,955, filed February 19, 1920, and Serial No. 360,949, filed February 24, 1920. While this-specific application of the invention is here pointed out for purposes of illustration, it is not to be inferred that the invention is limited thereto. `Dn the contrary rabbling mechanism emv17-17 on the interior of the socket.

bodying the present invention in widely differing specific forms may be employed in ore roasting and other mechanical furnaces or kilns. f

In the rabble mechanism here illustrated, 1.0 is the lower of two sections into which the upright rabble shaft is divided in this particular instance, the shaft sections ...being coupled together by suitable fastening means, such as bolts or the like (not shown), cooperating with coupling flanges 11. A one-piece rabblearm 12 is provided, at a locality intermediate its ends, Vwith a tapered boss or enlargement 13 integral therewith and of generally circularl cross section, litting snugly within a correspondingly taperse i ed supporting socket 14 disposed transversely at the lower end of the rabble' shaft. shown, the horizontal rabble armproject-s a substantial distance in opposite directions AsV from said socket, both projecting portions,

which in this instance are of unequal length, being adapted and arranged to carry detachable rabble teeth 15. Thev rabble arm is mounted in position on the upright shaft by thrusting that portion of the arm on the side next the smaller end of the tapered boss 13 y(at the left in Figs. 1, 4 and 7) through the supporting socket until .the cooperating surfaces of the boss and socket engage, that portion of the rabble arm being so dimensioned that it will pass freely through the socket. 1t will lbe understood that the rabble teeth are not mounted on'the arm until after the latter is assembled with its shaft, since the inside diameter of the receiving socket on the rabble shaft is only large enough to permit theV passage therethrough of the arm alone, or rather that portion of the arm extending from the smaller end of the tapered boss.

In order to ensure a snug joint, and to do this at low cost, I find it desirable to provide finished contacting or bearing surfaces only along the margins of the boss 13 and-socket 14, those for the boss being indicated at l16-16, cooperating with similar surfaces The metal between the finished bearing faces may be roughed down below the surfaces yof the faces in order to ensure contact only at said faces.

Means should be provided to prevent accidental longitudinal movement of the rabble arm in the socket. This may be accomplished in various ways within the broad scope of the invention, but the particular arrangement for this purpose showny in the drawings offers important practical advantages and is at present considered most desirable. The boss 13, which is hollow, (for a purpose hereinafter described) is provided Withan internaltransverse enlargement or web 18 to reinforce the arm at this point and to aiford sufficient metal to provide for iio a transverse slot or key-way 19. It is to be observed that the slot or key-way does not communicate with the hollow interior of the rabble arm and that the transverse enlargement only bridges the lower part of the hollow interior of the rabble arm and does not unnecessarily constrict the cooling passages to be hereinafter referred to. The walls of the socket 14 of the upright shaft are provided with transverse, alined slots 20 and 21 which are adapted to cooperate with the slot or keyway 19 of the rabble arm boss 13 when the latter is so positioned in the receiving socket 14 as to allow the insertion in the cooperating alined slots of the boss and socket of a key orwedge22, adapted to draw the boss firmly into the mounting socket and hold the parts rigid. In order that the wedge or key 22 may exert the proper wedging action to positively draw the boss into themounting socket, the cooperating slots or key-ways are so positioned in relation to each other in the socket and boss respectively that they will be slightly out of alinement when the boss abuts the socket when assembling the two. lVhen the wedge 22 is driven into the combined key way thus formed, it engages opposite side Walls of the key-way on the socket and boss, respectively tending to force the boss in a lateral direction with respect to the socket,l

and thereby firmly wedging the boss into the socket. Y

The smaller end face of the tapered socket in the rabble shaft is provided with a groove 23, so that if desired, the same vertical rabble shaft and socket may be used to support a single rabble arm, such as shown in my pending application Serial No. 359,955, the rabble arm being held in place by a pin passing through a slot in the arm and lying in said groove 23. This renders the vertical shaft and socket adaptable for either type of arm, which is a. point of practical convenience.

After the rabble arm 12 is assembled with its shaft 10 the teeth 15 and spacers 24, each provided with an attaching yoke 25, having hooks 26 fitting over longitudinal supporting ribs or ledges 27 on the rabble arm 12 and slidable therealong, are strung on over the ends of the arm and are held against accidental dislodgement from the arm by means of angular stop-pins 28, one of which is inserted in an aperture 29 at each end of the rabble arm. it will be observed that the means for locking the rabble shaft and arm together hold the parts rigidly together in such manner asl not to interfere with such slight movement of the teeth as may occur in operation. Moreover, the arrangement permits removal and replacement of the teeth without disturbing the locking means. Furthermore, in case a tooth accidentally breaks and is dislodged from the rabble it in no way effects the locked connection between the rabble shaft and arm. r

It will be observed that the teeth carried by the rabble arm on one side of the shaft 10 are in staggered or offset relation radially to those on the opposite side, so `that the teeth move in different paths and. are arranged to sweep over a'plurality of concentric contiguous annular hearth areas making up the total circular hearth area which the rabble mechanism is designed vto cover. By spacing the teeth a considerable distance apart as shown, difficulties due to semi-fused sticky material bridging across from one tooth to the next are largely elimi= nated. This relatively wide spacing apart of the rabble teeth is made possible bythe double arm construction; and by suspending the rabble teeth off-center,- as shown in Fig. 2, bridging up and down is also largely done away with. The rabble shaft 10 is rotated in such direction vthat in operation the tooth edges 15a are the front or advance edges.

The rabble shaft and arm are provided interiorly with cooling passages through which a cooling medium may be circulated. The rabble arm 12 is hollow and is provided interiorly with a partition wall 30, which divides the space inside into two passages 31 and 32 communicating only near the opposite ends of the arm as shown atv 33 and 34. The tapered boss 13 of the hollowk rabble arm 12 is provided with openings 35 and 36 communicating with passages 31 and 32", respectively, and lying on opposite sides of the partition wall 30, the upper edge 37 of which is therefore exposed in this locality. Thehollow interior of rabble shaft 10 is divided by theV partition wall 38 to form two independent passages 39 and 40. When the tapered boss 13 ofthe hollow rabble arm is properly positioned in the receiving socket 14 of the rabble shaft, the lower edge 41 of division wall 38 of the rabble shaft and the free upper edge 37 of wall 30 in the tapered boss abut, so that passage 39 registers with opening 35 and passage 40 registers with opening 36. Thus a cooling medium such as air, for example, may enter the rabble shaft through passage 39 and after passing successively` through passages 31, 33-34, and 32 of the rabble arm, flows into passage 40 of the rabble shaft and `may be discharged thence through opening 41.

It will be seen that the described construction makes it possible to assemble the double arm rabble member with its shaft by a direct straight thrust movement which is automatically stopped at the proper point necessary to ensure correct alinement and relative positioning of the several parts; and that the assemblage can be held together rigidly by simple locking means. Removal of the rab- 'prior application Serial No. 407,7 02, filed bination, a rabble shaft, a rabble arm detachably mounted on said shaft and means projecting transversely through said rabble shaft and -arni for locking the rabble arm against movement with respect to the rabble shaft.

2. Rabbling apparatus comprising in. combination, arabble shaft, a rabblearin detachably mounted on said shaft and projecting transversely through the shaft, the oppositely projecting rportions of said rabble arm being adapted to carry teeth, and means projectingY transversely through said rabble shaftandv arm for locking the rabble varm against movement with respect to the rabble shaft.

3. Rabbling apparatus comprising, in combination, a rabble shaft, a one-piece rabble Varm detachably mounted on said shaft and projecting transversely through the shaft, the oppositely projecting portions of Y said rabble arm being adapted to supportV removable teeth,

and means projecting transversely through said rabble shaft and arm for locking the rabble arm against movement with respect to the rabble shaft.

4. Rabbling' apparatus comprising, in combination, a rabble shaft, a rabble arm detachably mounted on said shaft andv projecting transversely through thev shaft, means integral with the arm to prevent relative movement in one direction of the rabble shaft and arm, and means projecting transversely through said .rabble shaft and arm to prevent relative movement of the rabble shaft and arm in the other direction.

j 5. Rabbling apparatus comprising, in combination, a rabble shaft provided .with a transversely disposed socket, a one-piece rabble arm having an integral enlargement intermediate its ends fitting said socket snugly and dividing said arm into two portions, 'bothof which are adapted to carry rabble teeth, and one of which is adapted to be passed through said socket until said enlargement abuts said shaft, and means pro-V jecting transversely through said socket and arm for locking the rabble .arni in this position. l 6. Rabblingapparatus comprising, in combination, a rabble shaft provided with a transversely disposed tapered socket, a rabble arm passing through said socket and having a tapered boss engaging said tapered socket, and means projecting transversely bination, a rabble shaft' provided with a` transversely disposed. tapered socket,`lthe walls of said socket being provided with a transverse aperture, a rabble `arm having 'a tapered boss provided with a transverse aperture, said arm being adapted to be passed through said socket `until said boss engages said socket and saidfapertures are infsubi stantial alinement, and a wedge in said apertures forcing said boss intoengagement with said socket. Y

9. Rabbling apparatus comprising, in com? bination, a hollowrshaft divided bya vertical partition into two passages, a transverse g lrabble arm removably mounted on said shaft and having two passages formed by a partition extending to points ad'acent veach end of the rabble arm, said rabble arm having tooth supporting portions extending, on opposite sides of said shaft andbeing provided with openings intermediate said portions communicating respectivelyV with the passages in said arm, and means project-ing transversely through said rabble shaft 'and arm for locking said arm to the shaft with the partition of the rabble arm in line with the partition of the shaft and abutting therewith, whereby saidV openings register with the respectivey shaft passages.

l0. Rabblin'g apparatus comprising, in combination, a hollow shaft provided with a transversely ldisposed tapered socket and divided by a vertical partition into two passages opening into said socket, a rabble arm passing through said socket and having a Vcentrally disposed tapered boss engaging said tapered socket, said rabble arm having two p assages formed by a vertically disposed partition extending to points adjacent each end of the rabble arm, the tapered boss on said rabblearm being provided with central openings communicating respectively with the passages in said arm, and means project'- and armY for locking said tapered boss in said tapered socket with the vertical partition of the rabble arm in line withV the vertical partition of the shaftv and abutting therewith, whereby said central openings register with the respective shaft passages. Y

izo

ving transversely throughsaid rabble. shaftv l1. Rabbling appara-tus comprising, in combination, a hollow shaft provided with a transversely disposed tapered socket and divided by a vertical partition into two passages opening into said socket, said socket being` provided with transverse alined slots, a holiow rabble arin passing through said socket and having a centrally disposed tapered boss engaging said tapered socket, said rabble arm having two passages formed by a vertically disposed partition extending to points adjacent each end of the rabble arm, the hollow tapered boss on said rabble arm being provided with central openings communicating respectively with the passages in said arm, said boss being provided with an internal slotted transverse boss, and a wedge passing through' the slots in the socket and internal boss for locking the tapered boss in said tapered socket with the vertical partition of the rabble arm in line with the vertical partition of the shaft and abutting therewith, whereby said central openings register with the respective shaft passages.

In testimony whereof I hereunto affix my signature.

LEWIS BAILEYSKINNER. 

